The concept of concerted practice laid down in Article 101(1), TFEU enables the European Commission (Commission), national competition authorities and national courts to prohibit certain forms of anti-competitive conduct among undertakings, which do not qualify as agreements. For an overview of Article 101(1), TFEU, see further, The prohibition on restrictive agreements. Concept of concerted practices: definition and underlying rationale Article 101, TFEU draws a distinction between agreements between undertakings, decisions by associations of undertakings (which we will not examine here) and concerted practices. The notion of an agreement implies that the parties adhere to a common plan that limits or is likely to limit their individual commercial conduct by determining how they will act or abstain from acting in the market. The concept of concerted practices refers to undertakings that knowingly engage in collusive behaviour to reduce uncertainty in the market. In contrast to an agreement, such collusive behaviour does not require the participants to adhere to a common plan that defines their actions in the market. Rather, it is enough if the participants 'knowingly adopt or adhere to collusive